Recently, in order to increase the memory capacities of semiconductor memory devices, various semiconductor memory devices have been developed which have a structure of three-dimensional stacking layers. For example, as a non-volatile semiconductor memory device having a stacked cross-point structure as one of such a type of semiconductor memory device, a variable-resistance-type memory such as a ReRAM or a PRAM that can be electrically rewritable has attracted attention. Such a variable-resistance-type memory is acquired by connecting a variable-resistance memory cell between both wirings at intersections of two wirings extending in directions perpendicular to each other. Generally, in a lower layer beneath the variable-resistance-type memory and a wiring connected thereto, a control circuit that controls the memory and the like are arranged. In addition, a contact layer, which is used for connecting the control circuit and the wiring, extending in the stacking direction is provided. Since a current to be sensed flows through the contact layer, a low-resistance contact structure needs to be formed between the contact layer and the wiring.